xAI's Colossus 2 Data Center Set to Nearly Double GPU Count by Year-End, Musk Says

Elon Musk posted a detailed expansion timeline for Colossus 2, his xAI supercomputer in Memphis, Tennessee, on the social platform X on Thursday, September 25, according to BigGo Finance and KuCoin. He says the facility currently runs 110,000 Nvidia GB200 chips and 440,000 GB300 chips, a total of 550,000. Three more batches of 220,000 GB300 chips are scheduled to come online in successive waves: next week, in November, and in late December.

If all three waves land on schedule, Colossus 2 alone would hold roughly 1.21 million chips by year-end, according to BigGo Finance's read of Musk's numbers. KuCoin reported a broader figure from the same Musk disclosure: combined with Colossus 1's roughly 230,000 GPUs (150,000 H100s, 50,000 H200s, and 30,000 GB200s), the two Memphis facilities already total about 780,000 chips today, and could reach 1.44 million across both sites if the December batch ships on time.

Not every estimate matches Musk's own numbers. Crypto Briefing, citing capital-cost and power projections from Epoch AI, puts Colossus 2's current chip count at 440,000 (330,000 B300s and 110,000 B200s), about 110,000 fewer than what Musk claims. Epoch AI's figures put the facility's capital cost so far at $35.8 billion, with a full buildout modeled at roughly $58 billion. TechTarget noted that SpaceX's buildout numbers have been "the subject of numerous conflicting reports" generally, even as independent satellite analysis from Epoch AI and SemiAnalysis has corroborated the overall pace of construction.

SpaceX completed its all-stock acquisition of xAI in February 2026, folding Colossus into the rocket company's business, according to BigGo Finance and TechTarget. The compute isn't just for Musk's Grok chatbot anymore. Crypto Briefing reports Anthropic is leasing capacity on the adjacent Colossus 1 cluster for roughly $1.25 billion a month, and Google is using about 110,000 GPUs on the Memphis site. BigGo Finance confirmed SpaceX signed a cloud services deal with Anthropic in May 2026 covering both Colossus facilities.

Musk also made a broader claim about where this leaves xAI in the AI race. Per KuCoin's report, he said a model competitive with Anthropic's "Fable" and OpenAI's GPT-6 could arrive within two to three months, and that xAI could "take the lead" in about six months. That is Musk's own prediction, not a verified benchmark result, and neither Anthropic nor OpenAI has responded to it in these reports.

The power problem underneath the chips

Running that many GPUs takes enormous power, and Colossus 2 has leaned on temporary gas turbines that Crypto Briefing says have drawn regulatory scrutiny over emissions. The long-term fix is a power plant across the state line in Southaven, Mississippi. TechTarget, citing an August 2026 SemiAnalysis report, says the Southaven site expanded from about 495 megawatts to 1.7 gigawatts of capacity. Crypto Briefing separately describes a 1.2-gigawatt permanent plant there targeted for full operation by mid-2027. The two figures don't line up cleanly, and neither source explains the discrepancy, but both confirm Southaven is central to keeping Colossus 2 running.

xAI has also quietly built what may be the largest battery installation in the country at the site. Canary Media counted 720 Tesla Megapack containers in satellite imagery from July 11, 2026, equating to roughly 2.8 gigawatt-hours of storage. xAI energy and data center developer Riley Trettel called it the nation's biggest battery in remarks to the Tennessee Valley Authority board on August 20, 2026, though Canary Media notes the company has released few technical details to back that claim.

None of this is happening in a vacuum for the people who live near it. Popular Mechanics profiled Jason Haley, a 47-year-old IT professional in Southaven who says turbine noise near his home has run past 1 a.m. and describes it as physically painful. Shannon Samsa, a 27-year-old physician assistant in the same city, told the outlet she had public health concerns about air pollution after Southaven Mayor Darren Musselwhite announced the new power plant, which he said would bring "several billion dollars" and "hundreds of new jobs" to the 60,000-person suburb. Those are real, competing stakes: an economic development win the mayor is selling to his constituents, against physical noise and air-quality complaints from residents living next to the turbines. No fine, violation finding, or formal enforcement action against the facility appears in these reports.

The unresolved question is whether Nvidia can actually supply chips at the pace Musk is promising. Data Center Dynamics has previously noted Nvidia shipped 3.76 million data center GPUs globally in a single year, and demand for the newest Blackwell-generation chips remains fierce across every major AI lab. Whether the December batch of 220,000 GB300s ships on Musk's schedule, and whether Southaven's grid and turbines can support the load without further resident complaints, will test this expansion more than the numbers in a single X post.